Introduction: Pop and Catch

About: More than 14 pulsating exhibits make the Children's Museum of Houston one of the top rated in the country. Packed with daily activities and invigorating performances, it’s the place where minds come out to pl…

A new twist on the ball and cup game while exploring transformation of energy!

This is one of the 48 projects for our Instructables: Made In Your Mind (IMIYM) exhibition at the Children’s Museum of Houston showing from May 26, 2012 - November 4, 2012. Produced in partnership with Instructables, IMIYM is an exhibit where families work together to build different fun, toy-like projects that help construct knowledge and skills related to science, technology, engineering, and mathematics while instilling a “do-it-yourself” attitude in kids so they feel empowered to explore, tinker, and try to make things themselves. To learn more, check out the article here.

This activity was an original created by Children's Museum of Houston staff and while we didn't find anything similar after a cursory search, there may be similar activities on Instructables. Often, the materials and process for building our projects are designed for use with a large number of visitors (we see over 800,000 annually) and the need to ensure safety in a mostly non-facilitated environment. So, yes, many of these projects have room for improvement in both materials and methodology, which is PRECISELY what we want to encourage the kids to do. So please do share your ideas for improvement and modifications!

Step 1: What You Need

2 - 9 oz plastic tumbler (you want the soft, #1 PETE plastic)
1 – 12” latex balloon (please do NOT use if you have latex allergies - I hope that would go without saying, but...)
1 – 1” Pom-pom (Note: You can substitute other items here like a small ball of paper, small ball of aluminum foil, or a cotton ball)
Masking Tape

We are selective in our materials for cost, ease of use, and safety due to our high traffic (800,000 visitors annually). So, for our purposes, this design worked best. But you may have other ideas - please share!

Step 2: The Video

We offer optional video segments of each step for this project in the actual exhibit. Here is a compilation of all the steps.

Step 3: Cut the Cups

Cut the bottom off of both tumblers (Note to kids: You may want a parent to help you with this). Make sure to trim the edges to remove any burrs.

Step 4: Add the Balloon

Cut the nozzle off the balloon leaving only the bulb part behind. Stretch the balloon over the mouth of one of the cups. It may help to have someone hold the cup. Make sure it is on tight – there shouldn’t be any dimples in the balloon. Tape the balloon to the cup.

Step 5: Finish the Pop and Catch

Tape the two cups together bottom-to-bottom to make an hourglass-like shape. Make sure no sticky parts to the tape are in any gaps on the inside.

Step 6: How to Play

To play, drop the pom-pom into the cups. Pinch the balloon, pull it back slightly (the further you pull back, the higher it goes), and let go. The pom-pom should pop up in the air. Try to catch it back in the cups.

The Pop and Catch works on transfer of energy. When you pull back on the balloon, it stretches, storing up energy in the form of potential energy. When you let go, that energy is turned into kinetic, or moving, energy as the balloon returns to its original shape. As it returns, the balloon pushes the pom-pom, transferring some of its kinetic energy into the pom-pom which launches it out of the cup.